Consider us your new best friend in the aquarium hobby


A  live stream on YouTube each Wednesday (audio and visual) week, and the release audio only on Spotify on the Sunday.

Is light-hearted fun, information, and different views on all things aquarium and tropical fish tank-related

Tips and tricks that we have learned over the years of keeping tropical fish.


Ziss CO2 Generator

The Ziss CO2 ZC-II is a revolutionary carbon dioxide generator that utilizes chemical neutralization for a precise and safe generation speed, controlled by the speed control valve. Its innovative pressure equivalent design ensures a consistent supply of high purity CO2 to your tank without the effects of temperature. When paired with our Ziss ZCR-160 generation kit, this generator can produce around 160g of CO2, lasting up to 45 days in a 100 Liter tank. For a dependable and efficient source of CO2 for your plant tank, look no further than the Ziss CO2 Generator.


Co2 solution is sold separately 

Customer Reviews

Based on 4 reviews
Matt Young
Ziss CO2 Reactor

As a beginner in aqua plants, i took the plunge and invested in a CO2 unit. The unit is easy to set up. Only tricky part is getting the timings of the droplets. The unit is small and doesn't take up much space. The good thing is that you don't need to buy the Ziss brand refills. The instructions already tell you the ingredients you need to buy. So happy with my purchase. Definitely recommend the Ziss brand.

Ant French

I like the CO2 generator so much, I purchased a 2nd one. This CO2 generator is very easy to use and adust and also looks great. My aquarium plants are now growing as if they are on steroids ! Amazing and rapid improvement to plant growth. I now realize that to grow aquarium plants a CO2 Generator is a must have, it completes the photosynthesis cycle and plants that supposedly don't need CO2 are astoundingly better off with CO2. I'm also amazed at the colour these plants are now producing ! Setting drip rate is easy and having a CO2 drop checker in the aquariums ensures peace of mind that the ppm rate is correct. Awesome :-) many thanks

Stephen penhey
not so good

this thing tacks some getting used to, I should have saved my money and bought the more expensive metal valves and co2 bottle

Great concept, not sure it works as well in reality tho...

I had high hopes for this DIY generator- in theory & according to the manufactures claims it should be more stable in terms of output & last longer than standard citric acid & baking soda DIY generators, but so far I have found that not to be the case with my 200L.

The good:
It comes with everything you need for a the generator- bottle, co2 hose & diffuser, so you just need to purchase the co2 ingredients (critic acid, baking soda & water).
It is much more compact than the typical double bottle method of co2 generation using the same ingredients.
It feels well made & the instructions are pretty simple to follow.
It does produce co2.

The not so good:
Setting the drip rate for co2 generation is somewhat fiddly (although easy enough to do given it is just turning a decently sized dial) but verrrrrrrrry time consuming given you have to wait around a good 30mins or more to time the drip rate multiple times a day, ideally every day to make sure it is putting out the correct amount of co2. This wouldn't be such an issue IF the drip rate stayed consistent after the first few days, but it doesn't seem to do that- generally the drip rate slows significantly over the course of a week & eventually over the course of a day, requiring adjusting daily if not multiple times a day to keep the co2 level somewhat consistent & every single time that means waiting a good 30+mins to time the drip rate, which becomes extremely tedious as you can't take your eyeballs off the generator at all in case you miss a drip, which also means any mark made as a reference to where the dial should to be for a certain drip/co2 rate becomes pointless.
You can't skip out on or get distracted during timing the drip/co2 rate when adjusting the dial- the one time I didn't wait around & time the drip rate over the course of 30-40mins, the drip rate ended up speeding up, thus becoming too high & by the time I got home, 80 percent of the solution had been dumped into the bottom chamber, spiking the co2 well into dangerous levels, so all the fish were gasping at the surface for air, which required an 80% water change to bring the co2 levels back down again- Not a mistake I recommend anyone else make given I got very lucky & only lost my elderly sparkling gourami pair :( The drip rate as the dial is turned seems to be rather delayed & inconsistent- turning the dial 2 markers could result in no speed up of the drip rate or could quadruple it over a 30 minute period.
You aren't supposed to turn it off overnight- the manufacturer recommends running it 24/7 & advises not turning it off or even down over night- I assume because of how fiddly & time consuming it is to readjust.
So far the diffuser isn't that good- the bubbles it puts out are too big, despite the infuser being tightened up as much as it can be & in use for a couple of weeks now.

I am using it on a tank which is at the higher end of the volume range that the manufacture says it is suitable for, so that maybe a factor in how poorly it is preforming thus far. I will refill & try it again on the 200L & see if it improves at all before I swap it over to a 65L that is running a standard citric acid & baking soda DIY co2 system to see how it goes on a smaller tank- I will update this IF there is an improvement in performance & will ensure I stay attentive while timing the drip rate to make sure there is no user error on my part again, in an effort to see if it really will put out co2 for 40days.

Thus far I'm not impressed with the performance of Ziss's CO2 generator comparative to the standard DIY generators for a pair of soft drink bottles using citric acid & baking soda, which tend to be simpler to adjust the rate of out put, keep a more consistent rate of co2 injection & can be turned off at night if desired.